1. Field of the Invention
The invention relates to a brushless DC motor with a Hall element.
2. Description of the Related Art
Conventional Hall-effect brushless DC Motors (BLDC Motors) include a stator on which a Hall plate is usually disposed to directly induce a main magnetic field and feed back the position signal of the rotor. The motors require a long magnetic tile and thus have high manufacturing costs. Another method to measure the position of a motor rotor is to directly mount a magnetic ring on the rotor to build a secondary magnetic field, through which the position of the magnetic ring is induced by a Hall element. However, disadvantage of the method is that because the magnetic ring is very close to the magnetic tile, the Hall element must be mounted inside a coil winding. In other words, the Hall element is enclosed by the coil winding; therefore current effects of the coil winding will affect the magnetic ring's secondary magnetic field, making it difficult for the Hall element to accurately measure the stator's position or resulting in inefficiency or even maloperations. Moreover, additional disadvantages may result from a complicated mounting structure and high costs.